With the help of an example explain how do tranquilizers control the feeling of depression?

Explanation

Noradrenaline is one of the neurotransmitters that plays a role in mood changes. If a person has low levels of noradrenaline in the body, then the signal-sending activity becomes low, and the person suffers from depression. In such situation, tranquilizers (antidepressant drugs) are used. These drugs inhibit the enzymes which catalyse the degradation of noradrenaline. As a result this neurotransmitter (noradrenaline) is slowly metabolized and can activate its receptor for longer periods of time, thus counteracting the effect of depression.